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Unbearable Lightness?

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Unbearable lightness?

To make cars frugal, they will have to become lighter—and more expensive

From The Economist.

WHEN it comes to motor vehicles there is widespread belief—at least in America—that bigger is not only better, but safer too. The assumption is that nothing beats having lots of steel around you in a crash. And it is true, to some extent. All things being equal, the driver of a large SUV (sports-utility vehicle) is less likely to be killed than the driver of a small car in a head-on collision between the two. The downside is that SUV drivers are far more likely than car drivers to die in solitary roll-over accidents induced by the vehicle’s own weight, its high centre of gravity and its truck-like suspension. Collisions with other SUVs can be deadlier still.

An excess of heavy metal imposes other penalties. American motorists are as aware as any that weight is the enemy of fuel economy. However, with pump prices low by international standards, the trade-off between safety and fuel consumption has understandably favoured the former. Adding air-bags, anti-lock brakes, stability control and side-impact beams has saved countless lives, but it has increased vehicle weights disproportionately. Cars and light trucks on American roads today are 30% heavier than they were in the mid-1980s.

Unfortunately, heavier vehicles need beefier engines to lug their extra girth around. As a result, much of the past quarter-century’s improvements in engine and vehicle design—low-friction materials, turbo charging, direct injection, variable valve-timing, cylinder deactivation, stop-start ignition, dual-clutch transmissions, better aerodynamics and low rolling-resistance tyres—have been mopped up by increases in vehicle weight.

It therefore comes as no surprise that last week’s pronouncement by the White House—that cars and trucks sold in America from the 2016 model year onwards will have to achieve a fleet-wide average of 35.5mpg (6.6 litres/110km)—should have awoken fears about vehicles becoming smaller and less safe in order to meet the latest fuel-sipping standards. The new corporate-average fuel economy (CAFE) figure, originally scheduled for 2020 but brought four years forward by the Obama administration, amounts to a 34% increase over today’s actual average of 26.4mpg.

How to achieve such a whopping increase in efficiency over so short a time? The trouble is that most of the low-hanging fruit in combustion engineering have been picked already. At best, the motor industry expects only a 15-20% further improvement can be squeezed from existing petrol engines and their transmissions. A new generation of plug-in hybrids and pure electric vehicles will doubtless help achieve the required goal. But even if their sales triple over the next five years, they will still account for less than 10% of America’s fleet of new cars by 2016.

Though themselves not cheap, clean diesels, with their 35% greater efficiency, would be a better bet—if only Americans could be persuaded to embrace them as Europeans have. Although no longer justified, the diesel’s reputation for being slow, smelly, noisy, unreliable and difficult to start in cold weather has lingered since the 1980s, when Detroit rushed out half-baked designs in response to the oil crisis.

But even if the demand for diesel cars were there, the fuel might not be—at least, not at a price Americans would be willing to pay. As it is, there is already a global shortage of diesel-making capacity. The catalytic crackers used in refineries throughout America are optimised to produce as much petrol as possible. Switching them over to the hydrocracking processes used widely in Europe and Asia for diesel production would take donkey’s years.

So it comes down to this: if half the increase in efficiency demanded by the new CAFE requirements is to come from further improvements in the power-train, then the other half will have to come from reductions in a vehicle’s weight. That prompts two immediate questions: how much will such a weight reduction add to prices, and will hard-won gains in vehicle safety be sacrificed in the process?

Given today’s materials and know-how, automotive engineers reckon a 10% reduction in vehicle weight yields a 6% improvement in efficiency. Meanwhile, trimming the fat from a vehicle’s bodywork, components and accessories costs roughly $2 a pound. Running the numbers for a typical car—say, a Toyota Camry weighing 3,260lb (1,500kg) and averaging 26mpg—suggests it would need to shed a little under a third of its weight, at a cost of roughly $2,000, to meet the 2016 standard. The Environment Protection Agency claims average prices on the forecourt will rise by only $1,300. Someone, somewhere, seems to have got their sums wrong.

In the end, the additional price for “adding lightness”—to borrow a phrase from the late Colin Chapman, the legendary founder of Lotus Cars—comes down to the materials used and how they are formed. To do the same job, HSLA (high-strength low-alloy) steels are up to 30% lighter than traditional carbon steels. They are already used in motor vehicles for components that have to withstand critical loads. Unfortunately, because of their higher strength and toughness, HSLA steels need 30% more energy to form them into useful shapes. Also, because their strength tends to be directional, they can fail under sudden loads from unexpected quarters.

One of the ways that Chapman added lightness to his cars, the use of composite materials such as carbon fibre and glass-reinforced plastic, is not that practical either. Lotuses are turned out in small numbers, but composites require too much manual work for volume production. So the only sensible material for reducing a conventional car’s weight while maintaining its strength is aluminium.

At present, aluminium accounts for 9% of a typical vehicle’s content—mostly in the form of castings and forgings for engine blocks, transmission cases, wheels and suspension parts. For the aluminium content to increase much further means using sheets and extrusions of the stuff for body panels and subframes. That will require further advances in laser welding and other bonding techniques to make production costs competitive.

The handful of aluminium-bodied cars in production have mostly been low-volume luxury models, such as the Honda NSX, the Audi A8 and the Jaguar XJ. Their body weights have typically been 10% to 15% lower than those of their steel equivalents. However, if all the parts made of iron and steel in cars today were replaced with aluminium, the vehicle would weigh 45% less. And it would be stronger, too. Pound for pound, aluminium is up to two-and-a-half times stronger than conventional steel—and can absorb twice the energy in a crash.

In short, making vehicles lighter does not mean they have to be smaller or less safe. If anything, cars with a high aluminium content have tended to be bigger and stronger than their steel-bodied predecessors. Replacing steel with aluminium allows additional interior space to be offered, along with larger crumple zones at the front and rear for even better crash protection, all without paying a heavy penalty in fuel consumption.

But there is a snag: cost. Aluminium is three to four times more expensive than steel. On the plus side, aluminium cars do not rust, and therefore last longer than conventional cars. And, at the end of their lives, they have a much higher scrap value. Add in the fuel saving, and the lifetime cost of an aluminium car—from raw material and manufacturing to daily use and final disposal—can be comparable to that of a conventional car. And the higher petrol prices go, of course, the sooner an aluminium car becomes as cheap overall as a conventional one.

The stumbling block in this analysis is that the person who walks into a showroom to buy a brand new aluminium car is unlikely to capture all those lifetime benefits. Nor is the manufacturer—at least, not immediately. So expect the initial sticker prices to be at least $2,000 higher for enlightened compact cars, and $4,500-6,000 more for trimmer luxury cars and SUVs. The only consolation will be not having to fill up the tank quite so often.

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great. how does the consumer win, especially when gas prices go up 40% or whatever CAFE does. Cuz that's what will happen.

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Another view that shows just how stupid the CAFE approach really is. The unimaginative idiots that write such legislation have no clue about the implications, and they just fall back on old solutions (CAFE) which failed in the past.

It's the wrong approach, and delays the sort of changes we really need to make.

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What's the problem with "added lightness"? cars are super porkers these days.

All this talk about the Hyundai Sonata's low weight at 3199lbs? Well Yippie... it's down to the weight of a 1989 Lesabre!

The Lacrosse, as much as I like it, is often cited as an example of being too heavy because it can weigh as much as B-Body station wagon!

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3200 is fine but too many cars down in that 2300-2500 pound range. Cars like that are too light for crosswinds, winter driving, and overall solidity. Part of the reason lots of folks bought huge SUV's was because they like that built like a tank feel. Especially in inclement weather, blizzard driving, etc.

What's the problem with "added lightness"? cars are super porkers these days.

All this talk about the Hyundai Sonata's low weight at 3199lbs? Well Yippie... it's down to the weight of a 1989 Lesabre!

The Lacrosse, as much as I like it, is often cited as an example of being too heavy because it can weigh as much as B-Body station wagon!

that 89 lesabre didnt push an extra 400 pounds of tech, wiring and airbags and other things that have been added since too.

to use your lacrosse example. the lacrosse is a just about right feeling car on the road. it doesn't feel light and insubstantial like many of the cheap midsizers, and it doesn't feel like a porky luxo barge. it feels like its got substance, and is somewhat agile at the same time. to me, its got the weight, size, and agility factor down pretty well.

Edited by regfootball
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All this talk about the Hyundai Sonata's low weight at 3199lbs? Well Yippie... it's down to the weight of a 1989 Lesabre!

Yes, but how many orders of magnitude safer is the Sonata? And with how many extra toys?

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Lightweight steel, carbon fiber, aluminum, and composite construction have all come a long way since 1988. These should have been added to cars in tandem with the other new technologies to keep vehicle weights relatively stable.

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to use your lacrosse example. the lacrosse is a just about right feeling car on the road. it doesn't feel light and insubstantial like many of the cheap midsizers, and it doesn't feel like a porky luxo barge. it feels like its got substance, and is somewhat agile at the same time. to me, its got the weight, size, and agility factor down pretty well.

Note that the 4100lbs Lacrosse is the CXS with AWD, but I agree with you on the feel of the Lacrosse, I just think it's pushed the weight a bit too far. The 3400lbs original CTS felt very solid and is very agile... and is only 200lbs more than a Sonata.

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Lightweight steel, carbon fiber, aluminum, and composite construction have all come a long way since 1988. These should have been added to cars in tandem with the other new technologies to keep vehicle weights relatively stable.

Why so? As this article mentioned, people in the US are willing to sacrifice fuel economy for safety (and size) because of the relatively low price of gas. In an ideal world, we could have a free lunch and have the light cars also be safe and cheap, but obviously there are trade offs in real life. Heavy, safe cars seems like a rational choice to me if gas is cheap.

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Note that the 4100lbs Lacrosse is the CXS with AWD, but I agree with you on the feel of the Lacrosse, I just think it's pushed the weight a bit too far. The 3400lbs original CTS felt very solid and is very agile... and is only 200lbs more than a Sonata.

the lacrosse i drove was fwd without sunroof and all that. i am guessing it was around 3800, just like my old 500 which also felt very solid on the road but wasnt as agile.

i will not comment on whether the sonata actually feels substantial or not as i havent driven it yet.

a lot of folks like the AWD option and will gladly put up with a couple hundred pounds in return for more traction.

i havent seen the CTS curb weight consistently posted that low.

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More weight doesn't mean it's safer. I bet you a Smart weighs a lot less than a Venture...but guess which is the deathtrap?

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Why so? As this article mentioned, people in the US are willing to sacrifice fuel economy for safety (and size) because of the relatively low price of gas. In an ideal world, we could have a free lunch and have the light cars also be safe and cheap, but obviously there are trade offs in real life. Heavy, safe cars seems like a rational choice to me if gas is cheap.

steel is the key. steel is cheap manufacture, but people also need to remember that many cars need to be repaired often, and crash costs with aluminum might push your insurance rates through the roof.

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Why so? As this article mentioned, people in the US are willing to sacrifice fuel economy for safety (and size) because of the relatively low price of gas. In an ideal world, we could have a free lunch and have the light cars also be safe and cheap, but obviously there are trade offs in real life. Heavy, safe cars seems like a rational choice to me if gas is cheap.

How long will your last statement be true? If you believe CERA, OPEC and the cornucopians there are at least 1,350 billion barrels of conventional oil in known reserves. But those are made up numbers. One famous example is Kuwait, which has only 48 billion barrels of proven (95% sure) and probable reserves (50/50 chance of being there) but continues to claim 102 billion barrels of proven reserves. Once you take out the lies, worldwide the figure is closer to 850 billion barrels, or quite possibly as little as 600 billion. The world uses over 30 billion barrels a year.

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the lacrosse i drove was fwd without sunroof and all that. i am guessing it was around 3800, just like my old 500 which also felt very solid on the road but wasnt as agile.

i will not comment on whether the sonata actually feels substantial or not as i havent driven it yet.

a lot of folks like the AWD option and will gladly put up with a couple hundred pounds in return for more traction.

i havent seen the CTS curb weight consistently posted that low.

I was off by 100lbs. The 2004 was 3500lbs.

More weight doesn't mean it's safer. I bet you a Smart weighs a lot less than a Venture...but guess which is the deathtrap?

A SMART will even wipe out half the hood area of an E-class while maintaining it's passenger compartment.

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How long will your last statement be true? If you believe CERA, OPEC and the cornucopians there are at least 1,350 billion barrels of conventional oil in known reserves. But those are made up numbers. One famous example is Kuwait, which has only 48 billion barrels of proven (95% sure) and probable reserves (50/50 chance of being there) but continues to claim 102 billion barrels of proven reserves. Once you take out the lies, worldwide the figure is closer to 850 billion barrels, or quite possibly as little as 600 billion. The world uses over 30 billion barrels a year.

That's not what I'm saying. I'm saying that with gas prices as they are (and perhaps, were), the cars for sale for here were rational. You were implying that all the manufacturers without exception were myopic and stupid for not building every car like the old XJ.

More weight doesn't mean it's safer. I bet you a Smart weighs a lot less than a Venture...but guess which is the deathtrap?

It's not a 1-1 relationship, but it's a very high correlation. You also need to compare apples to apples. The smart and Venture have very different dimensions. You'll note that the smart doesn't have nearly the fuel economy you would expect for a car that small, because the smart is very very heavy for a car of its size.

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That's not what I'm saying. I'm saying that with gas prices as they are (and perhaps, were), the cars for sale for here were rational. You were implying that all the manufacturers without exception were myopic and stupid for not building every car like the old XJ.

while it shouldn't have been taken to the XJ extreme, there could have been some things done to favor lightness. Throwing steel at a car to make it safer is the cheep way out.

However, facing the reality of our coming fuel issues, auto makers should be working on much lighter vehicles today. So that when the next gas prices spike and don't come back down. We won't be facing the same mad rush for efficiency we had last time.

There is a BIG reason GM put the 4-cylinder in the Lacrosse. As a country, we might need to dial back our expectations on beige sedan performance a bit.

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I was off by 100lbs. The 2004 was 3500lbs.

A SMART will even wipe out half the hood area of an E-class while maintaining it's passenger compartment.

yeah but that Smart will ping pong off a nice semi tractor and trailer......

That's not what I'm saying. I'm saying that with gas prices as they are (and perhaps, were), the cars for sale for here were rational. You were implying that all the manufacturers without exception were myopic and stupid for not building every car like the old XJ.

It's not a 1-1 relationship, but it's a very high correlation. You also need to compare apples to apples. The smart and Venture have very different dimensions. You'll note that the smart doesn't have nearly the fuel economy you would expect for a car that small, because the smart is very very heavy for a car of its size.

amazing how poor at fuel mileage the smart car is. its small, not a good car for general use, it's a toy. And yet you can't get much above 35 mpg in the real world with one. this is the road our leaders want us on. in smart cars.

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yeah but that Smart will ping pong off a nice semi tractor and trailer......

with passengers ping ponnging around within the passenger compartment

you jjust cant safely stop with 8" of crush zone vs. 3-4' of crush zone

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What's the problem with "added lightness"? cars are super porkers these days.

All this talk about the Hyundai Sonata's low weight at 3199lbs? Well Yippie... it's down to the weight of a 1989 Lesabre!

The Lacrosse, as much as I like it, is often cited as an example of being too heavy because it can weigh as much as B-Body station wagon!

The short answer is nothing. Because that is not what I was addressing.

What I am saying is that cars, and by extension their weight, are the wrong targets when attempting to solve this problem.

It is the fuels we should be concentrating on.

All the "added lightness" in the world won't make oil less finite. So instead of attempting to make the cars safer while mandating increased fuel economy, while trying to keep prices under control, while hoping the economy rebounds, we should be concentrating on viable alternatives in fuel. Otherwise, we stifle everything else in the hope that we might delay the end of the oil supply.

I think it's time to solve the problem instead.

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What I don't like is the separate standards for cars and trucks. Why should someone that wants a V8 performance car get penalized while someone that wants a V8 pickup is not. Diesel is going to play a big role in this too, automakers will have to push it, especially in SUVs and trucks.

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What I don't like is the separate standards for cars and trucks. Why should someone that wants a V8 performance car get penalized while someone that wants a V8 pickup is not. Diesel is going to play a big role in this too, automakers will have to push it, especially in SUVs and trucks.

While this sounds annoyingly Marxist, there is more of a "need" for V8 pickups in construction etc, while V8 cars tend to be toys. Not that that's a real defense of the different standards, but that probably explains why Congress did it that way.

Regarding diesel, I draw your attention to this part of the article:

"As it is, there is already a global shortage of diesel-making capacity. The catalytic crackers used in refineries throughout America are optimised to produce as much petrol as possible. Switching them over to the hydrocracking processes used widely in Europe and Asia for diesel production would take donkey’s years."

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Camino

is there a way to run an engine on straight ethanol? safely? reliably?

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is there a way to run an engine on straight ethanol? safely? reliably?

not that we could make 30 billion barrels of e100 a day

Edited by CanadianBacon94
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Camino

is there a way to run an engine on straight ethanol? safely? reliably?

Sure. Internal combustion engines can use a wide variety of fuels, both liquid and gaseous.

What we lack is production and distribution capacity for anything other than oil-based fuels.

What I hope for is some action on that front, and a diversification of both fuels and propulsion systems used in automobiles. We should never again have our economy rest on the supply of a single commodity.

We need electric cars, extended-range electric cars, cars that run on ethanol, natural gas, hydrogen, bio-fuels, propane, as well as gasoline and diesel. With each car optimised for its intended use as well as its intended energy source.

We should push flex-fuel vehicles, make retro-fits easier to do on older cars and trucks via EPA reform, assist in infrastructure development for alt fuels, and keep R&D going full-steam ahead.

There is simply no reason why we can't make it happen, to say otherwise is to make excuses and limit possibilities.

There is no "magic fuel", and that's a good thing - look what believing in one has already done to us.

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The short answer is nothing. Because that is not what I was addressing.

What I am saying is that cars, and by extension their weight, are the wrong targets when attempting to solve this problem.

It is the fuels we should be concentrating on.

All the "added lightness" in the world won't make oil less finite. So instead of attempting to make the cars safer while mandating increased fuel economy, while trying to keep prices under control, while hoping the economy rebounds, we should be concentrating on viable alternatives in fuel. Otherwise, we stifle everything else in the hope that we might delay the end of the oil supply.

I think it's time to solve the problem instead.

I agree with you that we should be addressing the fuel issue first... but I see no reason why we can't tackle weight as well. We have the technology already, it's not like someone has to go out and invent the stuff or build an infrastructure around it.

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